Core sampling apparatus

ABSTRACT

Apparatus for taking a plurality of sequential punch core samples in underwater sediments is provided. Core sampling tubes are driven into the sediments by hydraulic pressure acting through a central guide tube. The core sampling tube is withdrawn by hydraulic pressure applied through an annular space between the guide tube and a surrounding pipe. The hydraulic pressures are applied by a pair of hydraulic pumps using sea water as the fluid. A plurality of core sampling tubes are contained in a magazine and are fed to the guide tube one at a time for taking samples. The filled core tubes are returned to the magazine where they are retained and stored. First and second sets of drive cams on the magazine are operated alternately by reverse operation of the hydraulic pumps so that the containers in the magazine controllably advance only one container width at a time.

A United States Patent Koot [4' 1 Oct.'31, 1972 [54] CORE SAMPLINGAPPARATUS [72] Inventor: Nicholas L. Koot, Lafayette, La. Primary Exami''er Marvm Champion I Assistant Examiner-Robert A. l-lafer [73] AssigneezGlobal Marine Inc., Los Angeles, Attorney christie, Parker & Hale Calif.

. 22 Filed: Nov. 4, 1970 [571 ABSTRACT Appl 5 Apparatus for taking aplurality of sequential punch core samples in underwater sediments isprovided. Core sampling tubes are driven into the sediments by [52] U.S.Cl. ..175/6, 175/ 20, 175/52, hydraulic pressure acting through acentral guide tube 175/60 175/247 The core sampling tube is withdrawn byhydraulic [51] Int. Cl ..F21b 7/12 pressure applied through an annularspace between [58] Field of Search ..175/5, 6, 67, 246, 58, 59, theguide tube and a surrounding pipe The hydraulic 175/60 pressures areapplied by a pair of hydraulic pumps 25 0 2 using sea water as thefluid. A plurality of core sampling tubes are contained in a magazineand are fed to [56] References Cited the guide tube one at a time fortaking samples. The UNITED STATES PATENTS filled core tubes are returnedto the magazine where they are retained and stored. Flrst and secondsets of 2,392,683 l/ 1946 Mcwholfter ..175/52 drive cams on the magazineare operated alternately 2,277,989 3/1942 Kinnear ..175/247 X by reverseoperation of the hydraulic pumps so that 3,412,814 11/1968 Rosfelderm,..175/6 the containers in the magazine controllably advance 3,556,597 2/1969 Porter ..175/67 vonly one container width at a time 3,163,23812/1964 Malott ..175/5 3,561,547 2/1971 Pullos ..175/6 15 Claims, 5Drawing Figures [451 Oct. 31, 1972 United States Patent I [151 3,701,387Koot 51 Ot.31,1972

BACKGROUND There is considerable interest in obtaining core samples ofundersea sediments for geologic exploration, either for scientificinterest or for possible location of valuable minerals. It is preferredto obtain such samples elevation and partial cross section a multiplecore sampling apparatus constructed according to principles of by arelatively inexpensive punch coring where a hollow sample gathering tubeis forced or pushed into the sediment rather than by relativelyexpensive core drilling. Punch coring has, however, been significantlylimited by the buckling strength of core sampling tubes, and byoperational considerations, to only a few feet of sediment thickness. Ifit is desired to obtain core samples from more than the first few feetof sediment thickness, either an expensive core drilling operation hasbeen required or some means must be provided for re-entering a hole onthe sea floor after one core sample has been removed. This latter is adifficult operation at best, and in deep water is virtually impossiblewithout expensive equipment. It is, therefore, highly desirable toprovide apparatus for obtaining relatively long punch core samples inunderwater sediments without necessity of withdrawing the coringapparatus from the sea floor.

BRIEF SUMMARY OF THE INVENTION DRAWINGS These and other features andadvantages of the invention will be appreciated as the same becomesbetter understood by reference to the following detailed description ofa presently preferred embodiment when considered in connection with theaccompanying drawings wherein:

FIGS. la and lb illustrate in elevation and partial cross section amultiple core sampling apparatus constructed according to principles ofthis invention;

FIG. 2 illustrates a core sampling tube for use in the apparatus of FIG.1;

FIG. 3 illustrates a sampling tube container in the apparatus of FIG. 1;and

FIG. 4 illustrates in perspective a fragment of a magazine of aplurality of containers in the apparatus of FIG. 1.

Throughout the drawings like reference numerals refer to like parts.

DESCRIPTION In order to obtain a long core sample in practice of thisinvention, a plurality of short core samples are taken sequentiallyalong the length of the same hole. These punch core samples are takenwithout withdrawing the apparatus from the hole. FIG. 1 illustrates inthis invention. As illustrated in this preferred embodiment theapparatus comprises three principle sub-sections, namely, a feed andstorage magazine 11 for core sampling tubes, an operating sub-section 12immediately below the feed magazine, and an elongated coring pipe string13 below the operating section 12. The apparatus is large, taking coresamples about 10 feet long, and with a pipe string 13 in the order of250 feet or more in length.

During operation the entire apparatus is suspended from a ship (notshown) by a hoisting line 16 connected to the apparatus by a clevis 17.A sensing and control cable (not separately illustrated) is brought downalong the hoisting line for monitoring performance of the core samplerand controlling the various functions thereof. The clevis 17 isconnected to a rectangular case 18 forming the magazine housing. A pairof large open ports 19 are provided in the upper portion of the case 18to serve as a water outlet during reverse circu' lation, as hereinafterpointed out. The bottom 21 of the case is preferably made of an opengrill or with holes so that water and mud can freely pass therethrough.

A connecting tube 22 extends downwardly from the center of therectangular case 18 and connects at its lower end to the pipe string 13.The tube 22 provides mechanical support for a' conventional electricallydriven centrifugal pump and motor 23 employed for forcing a core tubeinto sub-sea sediments as hereinafter pointed out. The tube 22 alsoprovides mechanical support for a second conventional electricallydriven centrifugal pump and motor 24 opposite from the first pump 23,and employed for withdrawing filled core sample tubes from the sedimentsas hereinafter described. The two pumps 23 and 24 operate with seawaterdrawn in through pump suction ports 26.

The outlet 27 of the first pump 23 is connected to a guide tube 28, theinside of which is effectively a continuation of the inside of theconnecting tube 22 between the pipe string and the magazine. A springloaded check valve 29 having a flapper plate 31 that is spring biasedtoward a closed position shown in phantom blocking the outlet 27 of thepump 23 for preventing flow back into the pump when it is not inoperation. The flapper plate 31 is opened by operation of the pump 23 toa position shown in solid in FIG. 1 blocking the boreof the tube 22 forpreventing water from passing up the tube as the pump 23 is operated.

The second pump 24 has an outlet 32 in fluid communication with anannular space between the guide tube 28 and a surrounding pipe 33 whichcollectively form the principal length of the pipe string 13. At thelower end of the pipe 33 is a head 34 having a somewhat larger outsidediameter than the outside diameter of the pipe 33. The end of the guidetube 28 is also connected to the head 34 so that the lower end of theguide tube has a passage 35 through the head to the exterior of theapparatus. A fluid communication passage 36 is provided between theannular space inside the outer pipe 33 and the interior bore of theguide tube 28. Within the bore of the guide tube 28, near the bottom endof the pipe string, is a seat 37 having a smaller inside diameter thanthe inside diameter of the guide tube. The ends of the seat 37 aretapered to prevent sample tubes from sticking as they pass this point.

A typical punch core sample tube is illustrated in FIG. 2. The coresample tube comprises an elongated tubular barrel 41, which in a typicalembodiment may be about feet long. At the lower end of the barrel 41 isa conventional cutter head assembly 42 such as commonly employed forpunch coring. At the upper end of the core barrel 41 is an enlargedportion including a seat ring 43 which has an outside diameter smallerthan the inside diameter of the guide tube and larger than the insidediameter of the seat 37 (FIG. 1). Further up the core sampling tube is aconventional latching mechanism comprising a spearhead 44 connected to aside latch 46 in a conventional manner so that an axial force on thespearhead causes the latch 46 to protrude in the position shown in FIG.2 for locking the entire sample tube assembly into some selectedposition. During operation of the sample tube for sampling, the latch 46is retracted to permit ready sliding of the sampling tube assembly alongthe guide tube 29. A pair of opposed rubber cups 47 adjacent the upperend of the sample tube are provided for engaging the walls of theconnecting tube 22 and guide tube 29 so that hydraulic pressure can beapplied to the core sampling tube assembly.

Referring again to FIG. 1, within the rectangular magazine 18 is anassembly of several interconnected containers 51 shown in greater detailin FIGS. 3 and 4. The containers 51 are connected together so as to bein a parallel array with the axes of the containers in a substantiallyvertical orientation parallel to the axis of the connecting tube 22. Ina typical embodiment, such containers may be provided in the array, andthe rectangular magazine 18 is sufficiently long that all twenty of thecontainers 51 can be arrayed on either side of the center.

As seen in greater detail in FIGS. 3 and 4, each of the containerscomprises a cylinder 50 open at the bottom end and closed at the top endby a cap assembly 52. The cap assembly fits within the cylindricalcontainer and includes a pair of circulation holes 53 to permit passageof seawater. A lifting eye 54 is also provided in the cap so that onshipboard or the like the cap 52 can be lifted along with any elementsconnected thereto. Connected inside the cap 52 is a conventionalovershot latching mechanism 56 with which the spearhead 44 and latch 46(FIG. 2) on the core sample tube engage.

In order to operate the multiple core sampling apparatus, the entireassembly is lowered to the ocean floor on the hoisting line 16 until thehead 34 engages the sea floor 59. If it is desired to take a core sampleof the sediment commencing at the sea floor, the sampling operation cancommence at this time. Often, however, it is desired to obtain the coresample at a somewhat lower depth and, therefore, the pipe string islowered into the sea floor a preselected distance.

In order to drive the pipe string into the sea floor, the pump 23connected to the interior of the guide tube 28 is turned on so that ajet of seawater is forced out of the opening 35 at the lower end of thepipe string. The flow of water thro ugh'the opening rapidly erodes thesediments adjacent the head 34 and the entire drill string can belowered into a cylindrical hole 58 jetted into the sea floor 59.Penetration of sediments and similar soil by such water-jetting actionis well known. If desired, the second pump 24 can also be operatedduring the jetting operation for increased water flow. The first pump 23is always operated during the jetting operation in order to open thecheck valve 29 and cause the flapper plate 31 to block the upper end ofthe guide tube 29. After the drill string has been jetted into the seafloor by a selected distance such as, for example, 50 feet, the coresampling operation may proceed.

In order to take a core sample, a first container 51A is moved laterallyin the magazine 18, by a mechanism hereinafter described in greaterdetail, so as to be aligned with the connecting tube 22. Each of thecontainers 51 in the magazine has a punch core sampling tube such asillustrated in FIG. 2 contained loosely therein. Thus, when thecontainer 51A is aligned with the connecting tube 22, the core samplingtube drops therefrom and falls through the connecting tube 22 into theguide tube 29. During this operation the pumps 23 and 24 are OFF so thatthe check valve 29 leaves the passage clear.)

After the core sample tube has entered the guide tube 29, the first pump23 is turned on so that the check valve 29 opens the pump outlet and theflapper plate 31 closes the entrance to the connecting tube 22. Thisapplies hydraulic pressure to the upper end of the core sample tube,which is sealed against the guide tube by the rubber cups 47, and theflow of seawater from the pump pushes the core sample tube downwardlythrough the guide tube and punches it into the sediment beyond the head34 until the seat ring 43 engages the seat 37 to stop the downwardprogress of the core sample tube. As the core sample tube penetrates thesediments, the cutter head 42 cuts into the sediment and assures a coreof sediment being collected in the barrel 41.

After the core barrel 41 is filled with sediment by punching into thesea floor, the first pump 23 is turned off, thereby permitting theflapper valve 29 to close and the flapper plate 31 to clear the passagebetween the connecting tube 22 and guide tube 29. The second pump 24 isthen turned on and seawater flows through the annular space between thepipe 33 and the guide tube 28, and thence through the interconnectingpassage 36 at the lower end of the pipe string. This applies a hydraulicforce directed upwardly on the core sample tube, thereby withdrawing thetube from the sediments and propelling it upwardly through the guidetube and connecting tube back into the container 51A where the spearhead44 engages the overshot 56 for actuating the latch 46 and securing thecore sample tube to the cap 52 of the container. A hard rubber sleeve 61at the top of the connecting tube 22 is biased upwardly by a spring 62to close any substantial gap between the connecting tube and thecontainer so that the hydraulic force of the pump assures latching ofthe core sample tube in the container. Some seawater flows out of theopening 35 at the end of the pipe string, but the pressure still risesenough in the guide tube to force the sample tube upwardly.

After a first sample has been taken and the core sample tube returnedand stored in container 51A, the first pump 23 is again turned on forjetting the pipe string to a lower elevation in the hole 58corresponding to the length of core sample taken. When the pipe stringhas been so lowered, the magazine is again advanced until the secondcontainer 51B is aligned with the connecting tube 22, and a core sampletube therein is free to drop through the connecting tube into the guidetube 29 for a repeat of the operation just described. This operation isrepeated as often as desired until the core sample tubes in the severalcontainers 51 have each been used and the desired sample is storedtherein. As illustrated in FIG. 1, the containers 51 are at the lefthandside of the rectangular case 18 in a position where the contained coresampling tubes are loose therein. As these tubes are filled withsamples, the assembly of containers proceeds to the right in FIG. 1, andwhen all of the core sampling tubes are filled, the entire assembly isat the right side of this figure.

The mechanism for intermittently advancing the array of containers 51into alignment over the connecting tube 22 employs the same motors usedfor driving the pumps 23 and 24. The first pump 23 is connected with anoverride or cam clutch 63 which transmitsno motion when the pump isoperated in a forward direction and transfers motion when the pump motoris operated in reverse. The output of the overriding clutch 63 isconnected to a right angle speed reducer 64 having a drive roller 66 asits output. Similarly, an overriding or cam clutch 67 is connected tothe pump 24 so as to transmit no motion when the pump is operated in aforward direction and to transmit motion when the pump motor is operatedin the reverse direction. The output of the overriding clutch 67 isconnected to a right angle speed reducer 68 which has a roller 69 on itsoutput. The two rollers 66 and 69 are thus driven only when the motor ofthe respective pump 23 or 24 is driven in reverse. The two rollers 66and 67 are staggered, as illustrated schematically in FIG. 4, foroperating on different sets of drive cams.

A row of drive earns 71 is provided along one bottom edge of theassembly of containers, as seen in FIG. 4. A second row of drive cams 72is provided along the opposite bottom edge of the. assembly ofcontainers. One drive cam 71 is provided for every other container 51,and one of the second drive cams 72 is provided for each alternate oneof the containers 51 between those containers associated with a firstcam 71. Thus, in the illustrated embodiment, the second cams 72 are eachstaggered from the first earns 71, with alternate ones of the earns 71and 72 associated with successive containers.

The first driver roller 66 on the first pump 23 is aligned so as toengagethe lowermost surface of the cams 71. In a similar manner, thesecond roller 69 on the second pump 64 is aligned to engage the secondset of earns 72. Preferably the rollers 66 and 69 are arranged to befreewheeling when not being driven.

In operation, in order to advance the assembly of containers, one of thepumps, for example, the second pump 24, is operated in reverse so thatthe roller 69 in engagement with a cam 72 drives the assembly to theright. This driving engagement of the roller 69 and camming surface 72continues only along the length of one cam which corresponds to theadvancement of the assembly by one container. The roller 69 then ceasesto engage the camming surface 72 and advancement of the assembly stopseven though the pump 24 may still be running in reverse. As the assemblyadvances, however, the leading edge of one of the camming surfaces 71engages the presently freewheeling roller 66 connected to the other ofthe two pumps prior to disengagement of the roller 69 from the othercamming surface 72.

When it is desired to advance the assembly one additional container,"the motor associated with the other pump 23 is operated in reverse sothat the roller 66 in engagement with a cam 71 advances the entireassembly until that roller, in turn, loses engagement with the cammingface 71. Meanwhile the presently freewheeling roller 69 has engaged thenext cam face 72. In this manner, by operating the two pump motorsalternately in reverse, the assembly of containers is advanced one unitat a time to bring the containers successively into alignment with theconnecting tube 22. With such a mechanical arrangement there is norequirement for position sensors or precisely controlled operatingcycles on the pump motors. The motor need only be operated in reversefor a time longer than required to advance the assembly one container,and any excess of reverse operation is harmless. It should be apparentthat in the illustrated embodiment, the two rows of cams 71 and 72 arestaggered on the assembly of containers, and the two rollers 66 and 69,although displaced from each other, are effectively aligned for purposesof operation. The same effect can be obtained with pairs of aligned camsand two staggered rollers. It will also be apparent in lieu of cams, androllers; racks, gear sectors, and other driving engagements can beemployed.

By employing a pair of hydraulic pumps the control required in the coresampler is simplified. One pump is used to force the core sampling tubedown and the other to drive it back. These two functions could beobtained with a single pump and controlled valves. The single pump forsuch an embodiment would need to be large enough to effectively jetsediments for lowering the pipe string into the sea floor. In theillustrated embodiment, on the other hand, the two pumps can be smallerand they can be used together for jetting. The two pumps also providethe second function of advancing the container magazine incrementallywithout complex controls.

Although only one embodiment of multiple core sampling apparatus hasbeen described and illustrated herein, many modifications and variationswill be apparent to one skilled in the art. Thus, for example, in theillustrated arrangement, the array of containers for the core samplingtubes is linear. It will be apparent that the same result can beobtained with a cylindrical array of containers wherein the cylinder isrotated one container at a time for feeding core sample tubes in theapparatus. Many other modifications and variations will be apparent toone skilled in the art, and it is therefore to be understood that withinthe scope or the appended claims, the invention-may be practicedotherwise than as specifically described.

What is claimed is:

1. A multiple core sampling apparatus comprising:

means for forcing a core sampling tube into a material to be sampled;

means for withdrawing the core sampling tube from the sampled material;

means for feeding a plurality of empty core sampling tubes one at a timeto the means for forcing; and

means for receiving and storing a plurality of filled core samplingtubes from the means for withdrawing; and wherein the means for forcingcomprises means for applying hydraulic pressure in a forward directionon the core sampling tube; and

the means for withdrawing comprises means for applying hydraulicpressure in the rearward direction on the core sampling tube.

2. A core sampling apparatus as defined in claim 1 wherein the means forforcing further comprises a guide tube for the core sampling tube, andmeans for applying hydraulic pressure within the guide tube on arearward portion of the core sampling tube; and

the means for withdrawing comprises:

a pipe surrounding the guide tube and in fluid communication with theguide tube at a forward end thereof; and

means for applying hydraulic pressure within the pipe for application toa core sampling tube within the guide tube.

3.. A multiple core sampling apparatus as defined in claim 2 furthercomprising a seat within the guide tube at the forward end thereof forengagement with a seating member on a core sampling tube.

4. A core sampling apparatus as defined in claim 1 wherein the means forapplying hydraulic pressure comprises a hydraulic pump and furthercomprising;

means interconnecting the hydraulic pump and means for feeding foractuating the means for feeding upon reverse driving of the hydraulicpump.

5. A multiple core sampling apparatus comprising:

means for forcing a core sampling tube into a material tobe sampled;

means for withdrawing the core sampling tube from the sampled material;

means for feeding a plurality of empty core sampling tubes one at a timeto the means for forcing; and

means for receiving and storing a plurality of filled core samplingtubes from the means for withdrawing; and wherein the means for feedingcomprises:

a magazine with a plurality of containers for core sampling tubes; and

means for intermittently advancing the magazine an intervalcorresponding to one container; and

the means for receiving comprises means within each container forsecuring a filled core sampling tube therein.

6. A core sampling apparatus as defined in claim 5 further comprising amotor, and wherein forward operation of the motor actuates the means forforcing and reverse operation of the motor actuates the means forfeeding. I

7. A core sampling apparatus as defined in claim 5 further comprisingsecond means for intermittently advancing the magazine a distancecorresponding to one container and wherein the first and second meansfor intermittently advancing are operable only alternately, operation ofthe first means for advancing, enabling operation of the second meansfor advancing, and operation of the second means for advancing, enablingthe first means for advancing.

8. A core sampling apparatus as defined in claim 7 5 wherein the firstmeans for advancing the magazine comprises a plurality of first drivecams for every other container; and first means for driving the firstdrive cams; and wherein the second means for advancing the magazinecomprises a plurality of second drive cams for alternate containers inthe magazine from the first drive cams, and second means for driving thesecond drive cams.

9. A subsea punch coring apparatus for obtaining a plurality of punchcore samples in a plurality of punch core sample tubes comprising:

an elongated guide tube;

a pipe surrounding the guide tube for providing an annular conduittherebetween;

means for pumping seawater into the guide tube for 'forcing a punch coresample tube within the guide tube into subsea soil;

means for pumping seawater into the annular conduit between the guidetube and pipe for withdrawing a core sample tube from the subsea soil;and

means for feeding an empty punch core sampling tube into the guide tubecomprising:

a magazine including a plurality of core sampling tube receivingstations;

first means for intermittently advancing the magazine one station; and Isecond means for intermittently advancing the magazine one station, thefirst and second means for advancing being operable only alternately,operation of the first means enabling operation of the second means andoperation of the second means enabling operation of the first means.

10. A magazine as defined in claim 9 wherein the first means foradvancing comprises a plurality of first drive cams'for every otherstation, and means for driving the first drive cams; and wherein thesecond means for advancing comprises a plurality of second drive camsfor alternate containers from the first drive cams, and second means fordriving the second drive cams.

11. An underwater punch core sampling apparatus for obtaining aplurality of punch core samples in a plurality of punch core sampletubes comprising:

an elongated guide tube;

a pipe surrounding the guide tube for providing an annular conduittherebetween;

means for pumping seawater into the guide tube for forcing a punch coresample tube within the guide tube into subsea soil;

means for pumping seawater into the annular conduit between the guidetube and pipe for withdrawing a core sample tube from the subsea soil;and

means for feeding an empty punch core sampling tube into the guide tube;and wherein the means for pumping seawater into the guide tubecomprises:

a first pump;

a conduit connecting the first pump and the guide tube;

a two-position valve having a first position closing means for biasingthe valve toward the first position.

12. An underwater punch core sampling apparatus as defined in claim 11wherein the means for pumping water into the annular conduit comprises asecond pump and a conduit interconnecting the second pump and theannular conduit, said first and second pumps being operable alternatelyand simultaneously.

13. An underwater punch core sampling apparatus as defined in claim 1 1wherein the means for feeding comprises:

a magazine with a plurality of container means for loosely accommodatingan empty punch core sample tube in each container;

means associated with each container for securing a filled punch coresampling tube within each container means; and means for intermittentlyadvancing the magazine an interval corresponding to one container means;said apparatus further comprising a passage inter- Ali:

connecting the guide tube and a container means and wherein the meansfor pumping seawater for withdrawing is further for passing a filledpuch core sample tube through the guide tube and connecting passage to acontainer means.

14. An underwater punch core sampling apparatus as defined in claim 13wherein the means for intermittently advancing comprises:

means connected to one of the means for pumping for advancing themagazine upon reverse operation of the means for pumping. punch 15. Anunderwater punch core sampling apparatus as defined in claim 13 whereinthe means for feeding comprises:

a plurality of first drive means for every other container means;

a plurality of second drive means for every other container means in themagazine alternately with the first drive means;

first means for engaging the first drive means for advancing themagazine a distance equivalent to one container means;

means interconnecting the means for engaging and the first means forpumping only upon reverse operation of the first means for pumping;

second means for engaging the second drive means for advancing themagazine a distance equivalent to one container means; and

means interconnecting the means for engaging and means for pumping foroperation only upon reverse operation of the means for pumping.

1. A multiple core sampling apparatus comprising: means for forcing acore sampling tube into a material to be sampled; means for withdrawingthe core sampling tube from the sampled material; means for feeding aplurality of empty core sampling tubes one at a time to the means forforcing; and means for receiving and storing a plurality of filled coresampling tubes from the means for withdrawing; and wherein the means forforcing comprises means for applying hydraulic pressure in a forwarddirection on the core sampling tube; and the means for withdrawingcomprises means for applying hydraulic pressure in the rearwarddirection on the core sampling tube.
 2. A core sampling apparatus asdefined in claim 1 wherein the means for forcing further comprises aguide tube for the core sampling tube, and means for applying hydraulicpressure within the guide tube on a rearward portion of the coresampling tube; and the means for withdrawing comprises: a pipesurrounding the guide tube and in fluid communication with the guidetube at a forward end thereof; and means for applying hydraulic pressurewithin the pipe for application to a core sampling tube within the guidetube.
 3. A multiple core sampling apparatus as defined in claim 2further comprising a seat within the guide tube at the forward endthereof for engagement with a seating member on a core sampling tube. 4.A core sampling apparatus as defined in claim 1 wherein the means forapplying hydraulic pressure comprises a hydraulic pump and furthercomprising; means interconnecting the hydraulic pump and means forfeeding for actuating the means for feeding upon reverse driving of thehydraulic pump.
 5. A multiple core sampling apparatus comprising: meansfor forcing a core sampling tube into a material to be sampled; meansfor withdrawing the core sampling tube from the sampled material; meansfor feeding a plurality of empty core sampling tubes one at a time tothe means for forcing; and means for receiving and storing a pluralityof filled core sampling tubes from the means for withdrawing; andwherein the means for feeding comprises: a magazine with a plurality ofcontainers for core sampling tubes; and means for intermittentlyadvancing the magazine an interval corresponding to one container; andthe means for receiving comprises means within each container forsecuring a filled core sampling tube therein.
 6. A core samplingapparatus as defined in claim 5 further comprising a motor, and whereinforward operation of the motor actuates the means for forcing andreverse operation of the motor actuates the means for feeding.
 7. A coresampling apparatus as defined in claim 5 further comprising second meansfor intermittently advancing the magazine a distance corresponding toone container and wherein the first anD second means for intermittentlyadvancing are operable only alternately, operation of the first meansfor advancing, enabling operation of the second means for advancing, andoperation of the second means for advancing, enabling the first meansfor advancing.
 8. A core sampling apparatus as defined in claim 7wherein the first means for advancing the magazine comprises a pluralityof first drive cams for every other container; and first means fordriving the first drive cams; and wherein the second means for advancingthe magazine comprises a plurality of second drive cams for alternatecontainers in the magazine from the first drive cams, and second meansfor driving the second drive cams.
 9. A subsea punch coring apparatusfor obtaining a plurality of punch core samples in a plurality of punchcore sample tubes comprising: an elongated guide tube; a pipesurrounding the guide tube for providing an annular conduittherebetween; means for pumping seawater into the guide tube for forcinga punch core sample tube within the guide tube into subsea soil; meansfor pumping seawater into the annular conduit between the guide tube andpipe for withdrawing a core sample tube from the subsea soil; and meansfor feeding an empty punch core sampling tube into the guide tubecomprising: a magazine including a plurality of core sampling tubereceiving stations; first means for intermittently advancing themagazine one station; and second means for intermittently advancing themagazine one station, the first and second means for advancing beingoperable only alternately, operation of the first means enablingoperation of the second means and operation of the second means enablingoperation of the first means.
 10. A magazine as defined in claim 9wherein the first means for advancing comprises a plurality of firstdrive cams for every other station, and means for driving the firstdrive cams; and wherein the second means for advancing comprises aplurality of second drive cams for alternate containers from the firstdrive cams, and second means for driving the second drive cams.
 11. Anunderwater punch core sampling apparatus for obtaining a plurality ofpunch core samples in a plurality of punch core sample tubes comprising:an elongated guide tube; a pipe surrounding the guide tube for providingan annular conduit therebetween; means for pumping seawater into theguide tube for forcing a punch core sample tube within the guide tubeinto subsea soil; means for pumping seawater into the annular conduitbetween the guide tube and pipe for withdrawing a core sample tube fromthe subsea soil; and means for feeding an empty punch core sampling tubeinto the guide tube; and wherein the means for pumping seawater into theguide tube comprises: a first pump; a conduit connecting the first pumpand the guide tube; a two-position valve having a first position closingthe conduit and a second position closing the guide tube; and means forbiasing the valve toward the first position.
 12. An underwater punchcore sampling apparatus as defined in claim 11 wherein the means forpumping water into the annular conduit comprises a second pump and aconduit interconnecting the second pump and the annular conduit, saidfirst and second pumps being operable alternately and simultaneously.13. An underwater punch core sampling apparatus as defined in claim 11wherein the means for feeding comprises: a magazine with a plurality ofcontainer means for loosely accommodating an empty punch core sampletube in each container; means associated with each container forsecuring a filled punch core sampling tube within each container means;and means for intermittently advancing the magazine an intervalcorresponding to one container means; said apparatus further comprisinga passage interconnecting the guide tube and a container means andwherein the means for pumping seawater for withDrawing is further forpassing a filled punch core sample tube through the guide tube andconnecting passage to a container means.
 14. An underwater punch coresampling apparatus as defined in claim 13 wherein the means forintermittently advancing comprises: means connected to one of the meansfor pumping for advancing the magazine upon reverse operation of themeans for pumping. punch
 15. An underwater punch core sampling apparatusas defined in claim 13 wherein the means for feeding comprises: aplurality of first drive means for every other container means; aplurality of second drive means for every other container means in themagazine alternately with the first drive means; first means forengaging the first drive means for advancing the magazine a distanceequivalent to one container means; means interconnecting the means forengaging and the first means for pumping only upon reverse operation ofthe first means for pumping; second means for engaging the second drivemeans for advancing the magazine a distance equivalent to one containermeans; and means interconnecting the means for engaging and means forpumping for operation only upon reverse operation of the means forpumping.